Unwrap on the same spot
Found it, first select one face (of the pillar for exemple) then select -> select all by trait -> normal (now each pillar has one face selected) u -> reset

the faces are unwrapped on all the size of the image:

simply resize it (when reset the face got the ration of the uv/image, try to get the ratio of the face you have unwraped) and place it where you want: